Various 2-arylisoxazolin-3-one derivatives and synthesis methods thereof are described in Heterocycles, 20(6), 1123-1126(1983), Chemical and Pharmaceutical Bulletin, 30(9), 3097-3105, Heterocycles, 19(3), pages 515-520, Heterocycles, 19(3), pages 521-524, Journal of Heterocyclic Chemistry, 17(4), 727-731, Chemical and Pharmaceutical Bulletin, 19(7), 1389-1394, Japanese Patent Application (OPI) No. 104274/80 (the term "OPI" as used herein means an "unexamined published application"), Chemical Abstracts, Vol. 74, No. 17, 87947p, ibid., Vol. 75, No. 23, 140824v, ibid., Vol. 76, No. 23, 140775a, ibid., Vol. 97, No. 19, 16296u, etc.
However, 2-arylisoxazolin-3-one derivatives wherein the substituent at the 2-position of the isoxazolin nucleus is an aryl group substituted by an electron attractive group(s) having a higher electron attractive property than a chlorine group have never been known.